Over the past several years, photosharing has become widely accepted by photo enthusiasts. Many websites currently exist that allow users to upload digital images to the site for storage on a server and for viewing by others over the Internet. Oftentimes, images are grouped to form an album web page so that the user can invite others to view the album web page, as opposed to each individual image.
This approach to photosharing, however, presents some disadvantages. In particular, users are required to upload digital images to the site, which can be time consuming, and the site requires extensive storage capacity to store the images of all the users, which can become expensive.
To address these concerns, the assignee of the present invention has developed a web-based peer-to-peer photosharing system in which all workstations and computers (peers) in the network store images locally and act as servers to other users on the network. A central site accessible by all the peers provides additional functionality, such as coordinating the peers, providing search capabilities for the peers, purchase order fulfillment, etc.
FIG. 1 is a block diagram illustrating the web-based peer-to-peer photosharing system. The peer-to-peer photosharing system 20 includes a photosharing P2P network 22, which comprises multiple peer servers 24 running peer node software 26 and web server software 28. The peer node and server software 24 and 26 enable the users of the computers to share images with others in the network 22 through a web browser 30 without having to upload their pictures to a web site. A novel feature of the photosharing P2P network 22 is that it provides a hybrid peer-to-peer architecture for general HTTP/web browser configuration that incorporates a central proxy server 36 to coordinate networking traffic for peers behind firewalls, thus allowing access to peers behind firewalls by other peers and by visiting computers 32 not in the network 22. The proxy server 36 provides supporting services to the peers 24 as well as providing a path through which the visiting computer 32 accesses images from the peer servers 24 via a standard web browser 30. Allowing generic HTTP access to the images hosted on peer servers located behind firewalls becomes increasingly important as virtually all corporations use firewalls, and the use of software firewalls installed on user's home systems is becoming ubiquitous. As used herein, the peer servers 24, proxy server 36 and the visiting computer 32 may comprise any computing device, such as PCs, workstations, mobile phones, and PDAs, with components necessary for executing the appropriate software. Also, in a preferred embodiment, the physical communications network is the Internet, although any type of network could be used.
Each peer 24 stores album web pages and associated images locally in a database. Each album web page is associated with a descriptor that includes information about the album, such as which images are included in the album and who is permitted to see the album. For example, if the album is private, only the owner is allowed to view the album; if the album is “public,” then everyone can access the album; and if the album is “restricted,” then the album is accessible only to selected users. In this case, the descriptor includes an access list. The descriptor for each album web page is stored in a database (not shown) in the peer 24.
When a peer 24 receives a request (via the proxy server 36) to access an album web page from either another peer 24 or a visiting computer 32, the peer 24 accesses the database to retrieve the descriptor associated with the requested album web page. From the descriptor, the peer 24 determines whether the requester (e.g., peer user or user of the visiting computer) is permitted to access the album and which images are in the album web page. If the access is authorized, the peer 24 returns the album web page, which contains embedded images representing each of the album images.
Upon receipt of the album web page, the requestor's browser 30 interprets the web page and then initiates separate requests for each embedded image therein. When the peer 24 receives the request for the image, it accesses the database again to retrieve the descriptor for the album page in which the requested image resides to ensure: (1) that the requested image is actually in the associated album page; and (2) that the requestor has permission to access the album page and its contents, i.e., images.
One problem with routing images through the proxy server 36 is that it requires extra bandwidth. That is, the image must be moved twice; once from the peer server 24 to the proxy server 36, and then a second time from the proxy server 36 to the visiting computer 32. In addition, the path from the peer server 24 to the proxy server 26 generally has the longest latency because the peer server 24 is typically hosted in a user's home equipped with a cable modem or DSL that has an uplink speed much slower that the downlink speed. Thus, users may experience a significant delay when viewing images that are routed through the proxy server 36 due to the bandwidth limitations between the peer server 24 and the proxy server 36.
In addition, because peer servers 24 may be hosted in a variety of environments and host computers, there may be situations where the network to which the peer server 24 belongs may go off-line or the peer server 24 needs to go offline for maintenance. It is also possible that the peer server 24 is a mobile system, such as a laptop or tablet PC, which goes in and out of network service. All of these issues would cause the peer server 24 to disconnect from the proxy server 26 and stop serving guest requests. In this situation, the requesting guest would fail to receive the requested content from the off-line peer server 24.
Accordingly, there is need for a method and system for reducing the amount of network traffic between the peer server and the proxy server, and for serving content from a peer server regardless of whether the peer server is off-line in order to improve guest image viewing performance. The present invention addresses such a need.